UBIFS: Change ubifsload to not read beyond the requested size

Until now ubifsload pads the destination with 0 up to a multiple of
UBIFS_BLOCK_SIZE (4KiB) while reading a file to memory. This patch
changes this behaviour to only read to the requested length. This
is either the file length or the length/size provided as parameter
to the ubifsload command.

Signed-off-by: Stefan Roese <sr@denx.de>
This commit is contained in:
Stefan Roese 2010-11-01 17:28:00 +01:00
parent 9a2ea578bc
commit b1a14f8a1c

View File

@ -3,7 +3,7 @@
* *
* Copyright (C) 2006-2008 Nokia Corporation. * Copyright (C) 2006-2008 Nokia Corporation.
* *
* (C) Copyright 2008-2009 * (C) Copyright 2008-2010
* Stefan Roese, DENX Software Engineering, sr@denx.de. * Stefan Roese, DENX Software Engineering, sr@denx.de.
* *
* This program is free software; you can redistribute it and/or modify it * This program is free software; you can redistribute it and/or modify it
@ -567,7 +567,8 @@ dump:
return -EINVAL; return -EINVAL;
} }
static int do_readpage(struct ubifs_info *c, struct inode *inode, struct page *page) static int do_readpage(struct ubifs_info *c, struct inode *inode,
struct page *page, int last_block_size)
{ {
void *addr; void *addr;
int err = 0, i; int err = 0, i;
@ -601,17 +602,54 @@ static int do_readpage(struct ubifs_info *c, struct inode *inode, struct page *p
err = -ENOENT; err = -ENOENT;
memset(addr, 0, UBIFS_BLOCK_SIZE); memset(addr, 0, UBIFS_BLOCK_SIZE);
} else { } else {
ret = read_block(inode, addr, block, dn); /*
if (ret) { * Reading last block? Make sure to not write beyond
err = ret; * the requested size in the destination buffer.
if (err != -ENOENT) */
break; if (((block + 1) == beyond) || last_block_size) {
} else if (block + 1 == beyond) { void *buff;
int dlen = le32_to_cpu(dn->size); int dlen;
int ilen = i_size & (UBIFS_BLOCK_SIZE - 1);
if (ilen && ilen < dlen) /*
memset(addr + ilen, 0, dlen - ilen); * We need to buffer the data locally for the
* last block. This is to not pad the
* destination area to a multiple of
* UBIFS_BLOCK_SIZE.
*/
buff = malloc(UBIFS_BLOCK_SIZE);
if (!buff) {
printf("%s: Error, malloc fails!\n",
__func__);
err = -ENOMEM;
break;
}
/* Read block-size into temp buffer */
ret = read_block(inode, buff, block, dn);
if (ret) {
err = ret;
if (err != -ENOENT) {
free(buff);
break;
}
}
if (last_block_size)
dlen = last_block_size;
else
dlen = le32_to_cpu(dn->size);
/* Now copy required size back to dest */
memcpy(addr, buff, dlen);
free(buff);
} else {
ret = read_block(inode, addr, block, dn);
if (ret) {
err = ret;
if (err != -ENOENT)
break;
}
} }
} }
if (++i >= UBIFS_BLOCKS_PER_PAGE) if (++i >= UBIFS_BLOCKS_PER_PAGE)
@ -649,6 +687,7 @@ int ubifs_load(char *filename, u32 addr, u32 size)
int err = 0; int err = 0;
int i; int i;
int count; int count;
int last_block_size = 0;
c->ubi = ubi_open_volume(c->vi.ubi_num, c->vi.vol_id, UBI_READONLY); c->ubi = ubi_open_volume(c->vi.ubi_num, c->vi.vol_id, UBI_READONLY);
/* ubifs_findfile will resolve symlinks, so we know that we get /* ubifs_findfile will resolve symlinks, so we know that we get
@ -684,7 +723,13 @@ int ubifs_load(char *filename, u32 addr, u32 size)
page.index = 0; page.index = 0;
page.inode = inode; page.inode = inode;
for (i = 0; i < count; i++) { for (i = 0; i < count; i++) {
err = do_readpage(c, inode, &page); /*
* Make sure to not read beyond the requested size
*/
if (((i + 1) == count) && (size < inode->i_size))
last_block_size = size - (i * PAGE_SIZE);
err = do_readpage(c, inode, &page, last_block_size);
if (err) if (err)
break; break;